Is AppleCare+ for my iPhone valid outside the U.S?

iPhone warranties are not international and it is at the discretion of the local store as to whether or not they will honor the warranty. If the problem requires that the phone be completely replaced, there could be a problem if the identical model is not available.

Hello. I’ll be happy to help. I have provided a link to an apple support website. It should tell you all of the apple care plus available regions: Legal - AppleCare Protection Plan - Apple

[Edited by Moderator]

No.

AppleCare plus for phones is region limited.

The US models have a mm wave antenna that aren't in iPhones sold anywhere else.